Fix filesystem case sensitivity issue with IQP docs (#13414) (#13415)

(cherry picked from commit d81abce)

Co-authored-by: Eric Arellano <[email protected]>

Author: mergify[bot]

docs/conf.py

@@ -120,6 +120,14 @@
 napoleon_google_docstring = True
 napoleon_numpy_docstring = False
 
+# Autosummary generates stub filenames based on the import name.
+# Sometimes, two distinct interfaces only differ in capitalization; this
+# creates a problem on case-insensitive OS/filesystems like macOS. So,
+# we manually avoid the clash by renaming one of the files.
+autosummary_filename_map = {
+    "qiskit.circuit.library.iqp": "qiskit.circuit.library.iqp_function",
+}
+
 
 # ----------------------------------------------------------------------------------
 # Doctest